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| author | Serge Aleynikov <[email protected]> | 2013-01-21 15:36:43 +0100 |
|---|---|---|
| committer | Björn-Egil Dahlberg <[email protected]> | 2013-01-21 15:36:43 +0100 |
| commit | ab27e8699ef2a2bafe574158200993f184de3dc2 (patch) | |
| tree | a4365e182109d25ce049244b220844705b7d2a25 /erts/preloaded/src | |
| parent | 9f461fbaf0be7aba7c0b8b89be1f0b6f1141b7a5 (diff) | |
| download | otp-ab27e8699ef2a2bafe574158200993f184de3dc2.tar.gz otp-ab27e8699ef2a2bafe574158200993f184de3dc2.tar.bz2 otp-ab27e8699ef2a2bafe574158200993f184de3dc2.zip | |
Text representation of a float formatted using given options.
This BIF solves a problem of float_to_list/1 that doesn't allow
specifying the number of digits after the decimal point when
formatting floats.
float_to_list(Float, Options) -> string()
Float = float()
Options = [Option]
Option = {decimals, Decimals::0..249} |
{scientific, Decimals::0..249} |
compact
Returns a string which corresponds to the text representation of
a `Float` formatted using given options.
When decimals option is specified the returned value will contain
at most `Decimals` number of digits past the decimal point.
When `compact` option is provided the trailing zeros at the end
of the list are truncated (this option is only meaningful together
with the `decimals` option). When `scientific` option is provided,
the float will be formatted using scientific notation with
`Decimals` digits of precision. If `Options` is `[]` the function
behaves like `float_to_list/1`. When using `decimals` option and
the number doesn't fit in the static internal buffer of 256 bytes
the function throws `badarg`.
Diffstat (limited to 'erts/preloaded/src')
| -rw-r--r-- | erts/preloaded/src/erlang.erl | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl index 061db72dd8..3a40a6f97d 100644 --- a/erts/preloaded/src/erlang.erl +++ b/erts/preloaded/src/erlang.erl @@ -84,7 +84,8 @@ -export([display_nl/0, display_string/1, dist_exit/3, erase/0, erase/1]). -export([error/1, error/2, exit/1, exit/2, external_size/1]). -export([external_size/2, finish_after_on_load/2, finish_loading/1, float/1]). --export([float_to_list/1, fun_info/2, fun_to_list/1, function_exported/3]). +-export([float_to_list/1, float_to_list/2]). +-export([fun_info/2, fun_to_list/1, function_exported/3]). -export([garbage_collect/0, garbage_collect/1]). -export([garbage_collect_message_area/0, get/0, get/1, get_keys/1]). -export([get_module_info/1, get_stacktrace/0, group_leader/0]). @@ -711,6 +712,16 @@ float(_Number) -> float_to_list(_Float) -> erlang:nif_error(undefined). +%% float_to_list/2 +-spec float_to_list(Float, Options) -> string() when + Float :: float(), + Options :: [Option], + Option :: {decimals, non_neg_integer()} | + {scientific, non_neg_integer()} | + compact. +float_to_list(_Float, _Options) -> + erlang:nif_error(undefined). + %% fun_info/2 -spec erlang:fun_info(Fun, Item) -> {Item, Info} when Fun :: function(), |